i have installed apache tomcat6 for ubuntu 9.04 recenty.But it seems that some API's like servelet and http are not included althogh i have installed openJDK 1.6. somebody advised me to set JAVA_HOME path variable. BUT i am not able to do that and from where to do that. please explain the procedure.
Are you using the ubuntu-provided version ("sudo aptitude install tomcat6") or a version that you downloaded yourself? The ubuntu-provided version should run out of the box - you'll probably have to search for the locations where the different filetypes are buried. They are spread all over the system.
If you've downloaded a version from http://tomcat.apache.org, you've probably unzipped it somewhere and want to run it now. If you allow a shameless plug: Some time ago I've created a tomcat deployment checklist.
In both cases, try
If none of these help, please rephrase your question. To me it's not really clear what your exact problem might be. Please tell us, what version of tomcat you use (ubuntu's or a downloaded one?)